The surge is prompted by concerns of how Trump, a reality-TV star and real estate mogul who forged an unconventional and controversial path in politics filled with personal attacks and feuds, may use this country’s intelligence apparatus.

Privacy advocates have long fretted over the scope and potential use of U.S. espionage programs and tactics. Years before former contractor Edward Snowden revealed that the National Security Agency was engaged in widespread domestic surveillance, the government had been bolstering its ability to gather and keep massive amounts of data on people’s communications and online activities.

But Trump’s election, which has stoked fears of marginalization and violence among communities of color, Muslims, LGBT people and immigrants, has brought concerns over digital privacy to the public.

“The Obama administration drastically expanded and codified a lot of these programs that are now being handed over to Donald Trump,” said Evan Greer, the campaign director at activist group Fight for the Future. No matter who wields them, she said, “these types of mass surveillance programs that operate without accountability are simply too dangerous to exist.”

It remains unclear how Trump plans to use the government’s arsenal of espionage tools, including the controversial NSA programs that have operated with limited oversight and few restrictions since the terrorist attacks on Sept. 11, 2001. But his remarks on the campaign trail have left many security experts troubled.

The president-elect has called social justice group Black Lives Matter a “threat” and told conservative talk show host Bill O’Reilly over the summer that “at a minimum, we’re going to have to be watching.”

Trump could make many of those changes without the public even realizing, experts said, so long as companies comply.

Weakening protections from government spying could also open doors to others who want eyes on Americans’ data, said Gabe Rottman, a deputy director at the nonprofit Center for Democracy and Technology.

“Laws are simply letters on a page,” he said. “They’re not going to jump up and protect your rights.”

Pressuring tech companies to build more secure devices and protect user information, Snowden said, is a safer bet than relying on the integrity of government officials.

Earlier this year, Trump loudly criticized Apple for refusing to build special software to unlock an iPhone used by Syed Rizwan Farook, the gunman who killed 14 and injured 22 people in a mass shooting in San Bernardino last September. Trump encouraged his Twitter followers to boycott all Apple products.

At the time, Apple was cheered by many of its customers, tech professionals and security experts for its decision to resist the government’s demands. Complying, they believed, would set an unwieldy precedent for future government data requests.

On Friday, news reports indicated Trump had asked retired Lt. Gen. Michael Flynn, a three-star general who specialized in intelligence gathering, to serve as his national security adviser. It was not immediately clear whether Flynn shares Trump’s views on domestic espionage.

In the days after Trump was elected, downloads of the encrypted messaging app Signal spiked. It began trending in the App Store. Security experts and tech workers took to Twitter to espouse its virtues and encourage others to download it — particularly those planning to participate in protests.

The app, which was created by nonprofit Open Whisper Systems, offers a slew of privacy features including disappearing messages. ProtonMail, an encrypted email service, reported a similar jump in interest after the election.

Encryption helps prevent text messages, emails, phone calls and video chats from being intercepted during transmission, which is often how governments, law enforcement and hackers can spy on people’s communication.

When messaging or phone calls are encrypted, that means the communication is scrambled during transmission and then unscrambled by the intended recipient using a secret key, typically held by the sender, recipient and the app maker. With end-to-end encryption, which apps like Signal provide, the companies do not keep a copy of the key.

Security experts suggest starting small by downloading Signal or another messaging app with end-to-end encryption like Facebook’s WhatsApp, Viber or Apple’s iMessage and FaceTime. (Skype, Snapchat and Google Hangouts have weaker encryption, according to a recent Amnesty International report.)

Smarter use of existing tools may help, too.

“It may not seem like much, but even basic cyberhygiene can make a huge difference,” Rottman said.

Greer recommended using a hard-to-guess password — not a last name or “password123” — and enabling two-step verification when possible, using text messages or a code-generating app to add security.

If there’s a bright side to the fears Trump’s election has brought up in those who oppose him, she said, it may be that people are finally taking an interest in security and privacy.

“It’s exciting that people finally want to get educated,” Greer said. “It’s a good moment for that, and I think the challenge for people who are tech savvy and who have been banging our heads against the wall about this for the past eight years is to really try to make these things not feel overwhelming.”

Get a better password: Create a truly random password of 11 characters or more that is not repeated on other online accounts.

Enable two-step verification: This will require another step, like sending a text message to your phone, before you can log in. If someone gets your password, the text message may alert you to an attempt to break into your email or social media accounts.

Use strong encryption:Security experts suggest downloading Signal or similar messaging apps. The best use something called end-to-end encryption which even the app makers can’t unlock.